I Know Something You Don't Know
by syntheticxsunshine
Summary: Remus discovers how much Sirius knows about his feelings for Tonks through a series of smirkdeciphering, namecalling, and reminiscing of their hilarious Marauder days. Oneshot, RLNT.


**I Know Something You Don't Know**

By SXS

Disclaimer: I don't own any copyrighted aspects of this story nor did I intend any copyright infringement.

* * *

"Remus, could you pass the mashed potatoes, please?"

Remus Lupin reached his arms out and snatched the bowl of the starchy, snow-like substance out of Sirius's hands, which were currently using a spoon to scoop up nearly three-quarters of the food. Sirius shot him a disgruntled expression, and reluctantly handed them over to Remus. He turned to his left.

"Here Tonks," he handed the bowl to her, secretly cherishing the fact that he could look at her face. She really was rather attractive; he liked the sparkle of her eyes and the angle of her jaw. It was all very appealing, really, even when she was just looking at him blankly for a moment. But then came the inner-mantra of _too poor, too old, too dangerous_, and Remus forced himself to look away.

Not, however, before Tonks cracked a grateful smile and uttered a thank-you, which sent a sort of happy jolt through Remus's body. Unfortunately, the jolt of happiness accidentally prompted his hands to shake a bit, resulting in the smash of a bowl and mashed potatoes splattering on just about everyone.

"Nice one, Moony," teased Sirius, and Remus looked up at him sternly, and caught sight of Sirius's grin.

That grin.

He was grinning that grin for one of four reasons, two of which were topics not to be discussed at the dinner table. Remus decided to question him about that after dinner; whenever Sirius had _that_ expression on his face, _something_ was up.

* * *

Later, Sirius was sitting placidly in front of a roaring fire, sipping Butterbeer and flipping through old editions of _Dungbomb Daily_, which were pamphlets Zonko's used to give out during their time at Hogwarts about tips and tricks for pranks. Remus approached him apprehensively; there was a fifty-fifty chance he didn't need to know what Sirius was grinning about, but his curiosity at this point was just begging to know.

"Padfoot," he addressed curtly, hands in his pockets. Sirius turned his head around, that damned grin still plastered on his face.

"Yes Moony?"

"You were grinning like that again."

"Yes, Moony."

"…Well?"

"Well what? Can't a bloke just _grin_ once in awhile? Even _Voldemort_ must grin sometimes. Probably when my dear cousin Bella does him, ah…_favors_," Sirius chuckled at his own joke. Remus rolled his eyes.

"You know what I mean."

"No, I don't, actually," Sirius lied airily. "Do elaborate, dear Moony."

"Well, let me give you an example, then," Remus suggested, sitting down across from Sirius. "I remember in sixth year, you kept grinning like that because you got away with inserting a Dungbomb into Sniv—er, Snape's knickers and having it explode during Potions, and then yelling 'Snivelly's got explosive diarrhea!' about nineteen times. And _then_, that Tim Burgundy got blamed for it. Remember? Burgundy and those other two—Flemming and Hollis, I think, yeah—they were always trying to outdo us. We blamed so much on them so many times…." Sirius laughed hard, slapping his knee.

"That," he began, "Was an amazing day—and prank! And those Slytherin twits wouldn't have enough wit to outdo the Marauders even if they were each wearing a Diadem of Ravenclaw. But alas, that's not why I'm grinning now. Although your little mashed-potato explosion might've been about half the volume of Snivellus's—ah—_accident_."

"So, you haven't gotten away with something big, then," Regulus muttered. "How about we go in order of most likely to least? Since that was most likely, what's next? Hmm…haven't you got a lot of something you really shouldn't have too much of?"

"What the hell?" retorted Sirius, "Would you please stop speaking in double-negatives?"

"What I mean is," Remus continued, "I remember in fourth-year you snuck about four bottles of firewhiskey into the Common Room. And in fifth, it was fourteen bottles. And don't even get me started on sixth and seventh year—the amount we had was illegal even for of-age wizards. All those times, you had that grin."

"Those nights were a blast, Moony," Sirius replied devilishly. Then he added as an afterthought, "Even if I don't remember them…. It probably took about eight Headache-Dispelling Charms to get Prongs out of his hangover in the mornings, though. Probably only took two for me."

"Actually, it took five for you, on average," Remus reminded him smartly.

"Oh, whatever," Sirius dismissed his revealed tolerance level away with a flick of his wrist, "But that's not why."

"I figured," Remus grumbled monotonously. "Then…ah…I doubt it, but…."

"But what?" inquired Sirius, knowing precisely what.

"You know," Remus gestured his hand wildly, giving Sirius a meaningful look. He feigned not understanding it. "_Sirius_!" Remus exclaimed, not really wanting to suggest it.

"_Remus_!" he mocked.

"Fine, I'll be blunt," Remus reasoned, knowing being blunt was the only way to speak to Sirius in matters such as that, "I wasn't here last night and am pretty sure you were, but I highly doubt that you had sex last night."

"How do _you_ know?" Sirius teased, his eyebrows waggling comically.

"No one was here," Remus replied, "Unless it was with Kreacher. Although I guess _anything's_ possible." Sirius promptly flung a crumpled-up edition of _Dungbomb Daily_ at Remus, who let it hit him with a chuckle.

"Just joking, dear Padfoot," Remus said, in a mock-concerned voice.

"So," Sirius started up again, "What was the least likely thing that I could've been grinning about, eh? Something even less likely than me shagging Kreacher, is it?"

"There's only one option left," Remus said, almost hesitant to question it, "Sirius, are you smirking like that because, mind you, this is highly, _highly_ unlikely…you know something that I don't know?" Sirius flung another crumpled-up pamphlet at Remus before responding.

"Why yes, actually," he said, with an air of superiority. "Would you like to know what it is?"

"No," Remus replied, "I probably already do—you just don't know that I do."

"Dolt," muttered Sirius, disgruntled that he wouldn't be able to further flaunt his superiority.

"Git," retorted Remus.

"Prat."

"Twit."

"Werewolf."

"Mutt."

"Chocolate devour-er."

"Wormtail-snogger."

"That was on a dare!" exclaimed Sirius; clearly, mentioning his little smooch with Peter was out of bounds.

"You two were clearly in love," Remus taunted.

"Just like you with my second cousin?" Remus stared Sirius in the eyes, which were filled with mirth.

"Is _that_ what you know that I don't?"

"Well, I know that _you_ fancy her."

"How?"

"Please," Sirius rolled his eyes, "Unless you expect me to believe you get all shaky-handed, red-faced, and unable to form words that sound anything like English around Mad-Eye, who was sitting behind her, it's pretty obvious."

"Well I've got news for you, Padfoot," Remus declared.

"Yeah?" challenged Sirius, obviously thinking Remus was going to deny it.

"I already knew that."


End file.
